THE UTILIZATION OF FOOD IN ANIMALS 351 



is that they have no food value except that of the added 

 cream and sugar. The feeling of satisfaction which they 

 produce is due partly to the effect of heat on the stomach, 

 but chiefly to the stimulating effect of caffeine on the heart 

 and the nervous system. It is a serious mistake for children 

 and young people to drink either tea or coffee. A young and 

 spirited horse not only does not need the lash of a whip but 

 is greatly irritated by it, and so it sometimes is with human 

 beings and coffee. Even adults should use these beverages 

 with moderation or abstain from their use altogether if their 

 effect is marked. When an emergency arises, such as the 

 necessity of keeping awake all night or of working when 

 one is very tired, a cup of strong tea or strong coffee may 

 be an invaluable resource. In its lists of instructions for 

 first aid to the injured the lied Cross recommends strong 

 hot coffee as the very best stimulant. The economic impor- 

 tance of these beverages is indicated by the facts that in 1915 

 there was used in the United States 1,126,041,091 pounds 

 of coffee and 96,987,942 pounds of tea. 



Cocoa differs from tea and coffee in being much less stimu- 

 lating. This is a suitable beverage for children if it is not 

 made too strong and is made with milk. Doubtless many 

 older persons who drink coffee would be benefited by using 

 cocoa instead. 



355. Is alcohol a fcod? Alcohol is sometimes considered 

 a food because it can be burned or oxidized in the body to 

 liberate energy. It seems hardly safe, however, to describe 

 as a food a substance which has a marked depressing effect 

 on the body, similar to that of the hypnotic drugs such as 

 ether and chloroform. Alcohol was sometimes used as an 

 ansesthetic before the days of chloroform. In speaking of the 

 properties of foods one noted physiologist has said : " Neither 

 the substance itself nor any of the products of its transforma- 

 tion in the body must be injurious to the structure or activity 

 of any organ. If so, it is a poison and not a food." One 



